Which safety instruction is correct before working on a capacitor?

• A. Shut down the main breaker
• B. Discharge the capacitor first
• C. Follow procedures for discharging the capacitor
• D. Power can remain on while working on capacitor

Answer: (C)

Capacitors can store dangerous energy even after power is removed, so you must follow the established procedures for discharging the capacitor before any work. Merely shutting down the main breaker isn’t enough because the capacitor may still be charged or charged through other paths. Using the documented discharging procedures ensures you use the correct tools, discharge path, and safety steps, plus verify that the capacitor is truly de-energized with the right test instrument. Powering the circuit while you work is unsafe, and you should isolate the circuit and apply lockout/tagout as part of the process.